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More Human Cases of Bird Flu from Cows Identified, Unknown Exposure

More human cases of bird flu from cows have been reported. And the potential source has investigators scratching their heads.

Previous sources have involved direct contact with infected cows. Primarily those working on dairy farms. This new development changes everything.

Human Cases of Bird Flu from Cows

The increased concern of human cases of bird flu from cows comes from the growing number of American dairy cow herds infected with the virus. The latest information from the United States Department of Agriculture (USDA) shows 202 diary cow herds across 14 states have been impacted by bird flu infections.

According to the Centers for Disease Control and Prevention (CDC), there have been 14 human cases of avian influenza A(H5), also known as bird flu. Four of these were human cases of bird flu from cows. The remaining nine were exposed to poultry.

Latest of Human Cases of Bird Flu from Cows Was Not Occupational Exposure

What makes this recent case different is that there was no occupational exposure in the infected individual. An adult with underlying conditions was hospitalized on August 22, 2024 in Missouri.

A patient’s respiratory sample was positive for flu and batched to be sent to the state lab for subtyping. Through a routine surveillance program, that patient’s sample was identified as testing positive for bird flu.

The patient, who was admitted with chest pain, nausea, vomiting diarrhea, and weakness has since recovered. According to reports, the patient was severely ill and did not need intensive care treatment.

What makes this more complicated?

Missouri hasn’t reported any cattle outbreaks. In fact, while sporadic avian flu outbreaks in poultry have been reported in the state, none have been reported since February 2024.

Worries Over Person to Person Contact Exposure Spread

If the patient didn’t become sick from exposure to sick cows, how did they get the viral infection?

The complication doesn’t stop there.

More data is coming in regarding these human cases of bird flu.

Concerns over person to person contact exposure are creeping into the discussion.

Missouri health officials have recently reported another case involving household contact where a second sick individual presented the same symptoms as the confirmed case at the same time. Other reports of a healthcare worker experiencing mild symptoms have come to light.

From the specimens available, the genetic mutation found in bird flu in dairy cows was identified in these samples. Leading investigators to land on the theory that these people became sick from bird flu acquired from cows somehow.

But how?

There is no answer for that question at this time.

Could This Be a “One-Off” Case?

Could this new development of human cases of bird flu from cows without occupational exposure be a “one-off” case situation? Or do we have a new mode of transmission to identify?

The CDC considers that the contact exposure situation may have been a common exposure rather than a person to person transmission due to the onset of symptoms.

“The simultaneous development of symptoms does not support person to person spread but suggests a common exposure,” the CDC said.

A Human Test for This Novel Bird Flu Virus Is Needed

With human cases of bird flu from cows presenting similar symptoms to other illnesses, a human test for this novel bird flu virus is needed.

The CDC is currently working on making this suggestion a reality.

Or rather, the CDC, Aegis Sciences, Arup Laboratories, Gingko Bioworks, Laboratory Corporation of America, and Quest Diagnostics is working on it.

An initial investment of $5 million across five companies to scale up testing for flu has been made. These partnerships present a shift in the way the CDC has historically handled situations like this. Instead of being offered the opportunity after the CDC has performed the research, these private sector companies are given the green light to work on tests alongside the CDC.

Why?

According to a spokesperson, this approach is an effort to make testing available earlier and avoid delays during emergencies. The idea is likely to create at-home version of tests much like those available for COVID-19.

How Do Humans Get Bird Flu Anyway?

Given the current information, it seems that humans can become sickened with bird flu from both poultry and cows. Information on other exposure risks is not available at this time.

Transmission occurs when the virus gets into a person’s eyes, nose or mouth, or is inhaled. This can occur from aerosolized droplets in the air, from dust contaminated with the virus, or from touching something contaminated and touching the eyes, nose, or mouth.

Human Symptoms of Bird Flu

Bird flu affects humans differently than it does in poultry. Even differently from cows. It seems humans experience their own set of symptoms when infected with the virus.

Common symptoms of bird flu in humans include:

  • Conjunctivitis (eye redness)
  • Mild flu-like upper respiratory symptoms
  • Cough
  • Sore throat
  • Runny or stuffy nose
  • Muscle or body aches
  • Headache
  • Fatigue
  • Shortness of breath or difficulty breathing
  • Pneumonia requiring hospitalization
  • If present, fever of 100° F or greater

Some people infected with bird flu may show no signs or symptoms. Others may experience a combination of those above or even diarrhea, nausea, vomiting, or seizures.

How is Bird Flu Diagnosed?

Bird flu is not diagnosed by symptoms. These symptoms are often confused with other illnesses or not present at all. Only a specialized laboratory test can accurately diagnose bird flu in humans.

This testing is more accurate when a swab is obtained during the first few days of illness.

Where Did the Illness Come From?

The bird flu virus has shown off its ability to mutate to infect other host species. We have seen reports of bird flu in dairy cows, cats, dogs, and mice. Where did these new non-occupationally acquired cases of bird flu in humans from cows come from?

Is it from the food supply?

We expect that our nation’s scientists are working around the clock to find out. Stay tuned as more information becomes available.

Stay in Touch with Make Food Safe!

If you’d like to know more about food safety topics in the news, like “More Human Cases of Bird Flu from Cows Identified, Unknown Exposure,” check out the Make Food Safe Blog. We regularly update trending topics, foodborne infections in the news, recalls, and more! Stay tuned for quality information to help keep your family safe, while The Lange Law Firm, PLLC strives to Make Food Safe!

By: Heather Van Tassell (contributing writer, non-lawyer)

Heather Van Tassell

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